Flipped touchscreen X axis on Makerfactory 3.5“ display

Building Zynthian
5

I went to the webpage of my screen (waveshare) and followed their instructions.

having a 99-calibration.conf in /etc/X11/xorg.conf.d/

Section "InputClass"
    Identifier      "calibration"
    MatchProduct    "stmpe-ts"
    Option  "Calibration"   "3807 174 244 3872"
    Option  "SwapAxes"      "1"
EndSection

In config.txt

hdmi_drive=1
hdmi_group=2
hdmi_mode=1
hdmi_mode=87
hdmi_cvt 800 480 60 6 0 0 0
display_rotate=2

in /etc/X11/xorg.conf.d/40-libinput.conf
besides other sections:

Section "InputClass"
        Identifier "libinput touchscreen catchall"
        MatchIsTouchscreen "on"
	    Option "CalibrationMatrix" "-1 0 1 0 -1 1 0 0 1"
        MatchDevicePath "/dev/input/event*"
        Driver "libinput"
EndSection